Flux for soldering aluminum.



rrn sas on.

CARL F. KRIEWS, OF CLEVELAND, OHIO, ASSIGNOR OF ONE-HALF TO FRANK C.KRIEWS,

' OF CLEVELAND, OHIO.

FLUX FOR SOLDIERING ALUMINUM.

No Drawing.

To all whom it may concern:

Be it known that I, CARL F. Kn nws, a citizen of the United States,resident of Cleveland, county of Cuyahoga, and State of Ohio, haveinvented a new and useful Improvement in Fluxes for Soldering Aluminum,of which the following is a specificaand another element of any othermetal.

The said invention consists of means hereinafter fully described andparticularly set forth in the claim.

As is well known to those skilled in the art, great difiiculty has beenmet in solderlng aluminum in an eflicient, economical and permanentmanner and especially in a man ner whereby aluminum may be soldered inthe manner heretofore employed in the Specification of Letters Patent.

Patented Dec. 19,- 19116.

Application filed April 21, 1916. Serial No. 92,657.

well-known and common practice of solder- 1ng tin for example.

In applying this flux I find it desirable to first scrape or otherwiseabrade the aluminunr surface to which the solder is to be applied, andthen apply the free fatty acid to such surface. Anprdinary solderingiron1s then heated and applied to a stick of ordinary commercial solder,which consists usually of an alloyof one-eighth of tin and seven-eighthsof lead, the soldering iron being heated, as is usual, to a temperatureof 375 to 450 F. WVhere acomparatively large surface or seam is to besoldered, I find 1t advantageous to preheat the adjoining surfacesslightly before applying the fiux and solder.

By means of the above-described flux, I have found that such ordinarysolder may be securely and permanently attached to an aluminum surfaceand that such solder hence may be successfully used in joining togethertwo aluminum elements. that certain substances which are derived from,are compositions of or mixtures with these free fatty acids, may alsoaccomplish the hereindescribed purpose to a more or less satisfactorydegree. as for instance, olive oil, cottonseed oil oi-"linseed oil,which are glycerids of a fatty acid. This form of my invention I haveclaimed in a separate application for U. S. Letters Patent, filedFebruary 10, 1916, Serial No. 77,367.

' Having fully described my invention,what I claim and desire to secureby Letters Patent is A flux for soldering aluminum comprising a fattyacid such as oleic, palmitic, stearic,

- obtainable from animal fats.

' Signed by me, this 19th day of April, 1916.

CARL F. KRIEWS.

I have also found.

